[dm-devel] split scsi passthrough fields out of struct request V2

[Jens Axboe]

> On Jan 30, 2017, at 5:12 PM, Bart Van Assche <Bart.VanAssche at sandisk.com> wrote:
> 
>> On Fri, 2017-01-27 at 09:56 -0700, Jens Axboe wrote:
>>> On 01/27/2017 09:52 AM, Bart Van Assche wrote:
>>> [  215.724452] general protection fault: 0000 [#1] SMP
>>> [  215.725060] Call Trace:
>>> [  215.725086]  scsi_disk_put+0x2d/0x40
>>> [  215.725110]  sd_release+0x3d/0xb0
>>> [  215.725137]  __blkdev_put+0x29e/0x360
>>> [  215.725163]  blkdev_put+0x49/0x170
>>> [  215.725192]  dm_put_table_device+0x58/0xc0 [dm_mod]
>>> [  215.725219]  dm_put_device+0x70/0xc0 [dm_mod]
>>> [  215.725269]  free_priority_group+0x92/0xc0 [dm_multipath]
>>> [  215.725295]  free_multipath+0x70/0xc0 [dm_multipath]
>>> [  215.725320]  multipath_dtr+0x19/0x20 [dm_multipath]
>>> [  215.725348]  dm_table_destroy+0x67/0x120 [dm_mod]
>>> [  215.725379]  dev_suspend+0xde/0x240 [dm_mod]
>>> [  215.725434]  ctl_ioctl+0x1f5/0x520 [dm_mod]
>>> [  215.725489]  dm_ctl_ioctl+0xe/0x20 [dm_mod]
>>> [  215.725515]  do_vfs_ioctl+0x8f/0x700
>>> [  215.725589]  SyS_ioctl+0x3c/0x70
>>> [  215.725614]  entry_SYSCALL_64_fastpath+0x18/0xad
>>> 
>> 
>> I have no idea what this is, I haven't messed with life time or devices
>> or queues at all in that branch.
> 
> Hello Jens,
> 
> Running the srp-test software against kernel 4.9.6 and kernel 4.10-rc5
> went fine. With your for-4.11/block branch (commit 400f73b23f457a) however
> I just ran into the following:
> 
> [  214.555527] ------------[ cut here ]------------
> [  214.555565] WARNING: CPU: 5 PID: 13201 at kernel/locking/lockdep.c:3514 lock_release+0x346/0x480
> [  214.555588] DEBUG_LOCKS_WARN_ON(depth <= 0)
> [  214.555824] CPU: 5 PID: 13201 Comm: fio Not tainted 4.10.0-rc3-dbg+ #1
> [  214.555846] Hardware name: Dell Inc. PowerEdge R430/03XKDV, BIOS 1.0.2 11/17/2014
> [  214.555867] Call Trace:
> [  214.555889]  dump_stack+0x68/0x93
> [  214.555911]  __warn+0xc6/0xe0
> [  214.555953]  warn_slowpath_fmt+0x4a/0x50
> [  214.555973]  lock_release+0x346/0x480
> [  214.556021]  aio_write+0x106/0x140
> [  214.556067]  do_io_submit+0x37d/0x900
> [  214.556108]  SyS_io_submit+0xb/0x10
> [  214.556131]  entry_SYSCALL_64_fastpath+0x18/0xad
> 
> I will continue to try to figure out what is causing this behavior.

That's a known bug in mainline. Pull it into 4.10-rc6,
or use my for-next where everything is already merged.